//banner轮播图
var omask = document.getElementsByClassName("mask")[0];
var oimg = document.getElementById("ban_img");
var index = 0;
var imgarr=[
    ["./upload/walk1_mask.jpg","./upload/walk1_img.jpg"],
    ["./upload/walk2_mask.jpg","./upload/walk2_img.jpg"],
    ["./upload/walk3_mask.jpg","./upload/walk3_img.jpg"],
    ["./upload/walk4_mask.jpg","./upload/walk4_img.jpg"],
    ["./upload/walk5_mask.jpg","./upload/walk5_img.jpg"]];
var timer =setInterval(function(){
    index+=1;
    omask.style.backgroundImage="url("+imgarr[index][0]+")";
    oimg.src=imgarr[index][1];
    if(index==4){
        index=0;
    }
},5000);